American firearms manufacturer J. Stevens Arms & Tool Company introduced the cartridge in 1887[4] by combining the casing of the .22 Long with the 40-grain (2.6 g) bullet of the .22 Extra Long. The round owes its origin to the Flobert BB cap of 1845 through the .22 Smith & Wesson cartridge of 1857. It is one of the few cartridges that are accepted by a large variety of rifles, as well as pistols. The .22 Long Rifle and related cartridges (.22 Short, .22 Long, and .22 Extra Long) use a heeled bullet, which means that the bullet is the same diameter as the case, and has a narrower "heel" portion that fits in the case.

Low cost, minimal recoil, and relatively low noise make the .22 LR an ideal cartridge for recreational shooting, initial firearms training, small-game hunting, and pest control. Used by Boy Scouts in the United States for the rifle shooting merit badge,[5] the cartridge is popular among novice shooters and experts alike. The rimfire round is commonly packaged in boxes of 50 or 100 rounds, and is often sold by the 'brick', a carton containing either 10 boxes of 50 rounds or loose cartridges totalling 500 rounds, or the 'case' containing 10 bricks totalling 5,000 rounds. .22 LR ammunition is among the least costly cartridge ammunition available.[6]

A wide variety of rimfire ammunition is available commercially, and the available ammunition varies widely both in price and performance. Bullet weights among commercially available ammunition range from 20 to 60 grains (1.3 to 3.9 g), and velocities vary from 575 to 1,750 ft/s (175 to 533 m/s). Promotional loads for plinking can be purchased in bulk for significantly less cost than precision target rounds. The low cost of ammunition has a substantial effect on the popularity of the .22 LR. For this reason, rimfire cartridges are commonly used for target practice.

The low recoil of the cartridge makes it ideal for introductory firearms courses. Novice shooters can be surprised or frightened by the recoil of more powerful rounds. Beginners shooting firearms beyond their comfort level frequently develop a habit of flinching in an attempt to counter anticipated recoil. The resulting habit impedes correct posture and follow-through at the most critical phase of the shot and is difficult to correct. With high recoil eliminated, other errors in marksmanship technique are easier to identify and correct.

Available for this round are AR-15 upper receivers and M1911 slide assemblies. Many handgun manufacturers have an upper pistol conversion kit to make it shoot .22 ammunition. These rimfire conversions allow shooters to practice inexpensively while retaining the handling characteristics of their chosen firearms (with reduced recoil and muzzle blast). Additionally, .22 conversion kits allow practice at indoor ranges which prohibit high-power firearms. Owners of guns that use gas systems, such as AR-15 sport style rifles, normally avoid firing non-jacketed .22 LR ammunition, as the use of unjacketed ammunition may cause lead-fouling of the gas-port inside the barrel and costly gunsmithing procedures.

Annual production is estimated by some at 2–2.5 billion rounds.[7][8] The NSSF estimates that a large percentage of the US production of 10 billion cartridges is composed of .22 LR.[9] Despite the high production figures there have occasionally been shortages of .22 LR in the continental United States, most notably during the 2008–13 United States ammunition shortage.

Performance depends on barrel length and the type of action. For example, it will often perform differently in a bolt-action rifle than in a semiautomatic rifle. The .22 LR is effective to 150 yd (140 m), though practical ranges tend to be less. After 150 yd, the ballistics of the round are such that it will be difficult to compensate for the large "drop". The relatively short effective range, low report, and light recoil has made it a favorite for use as a target-practice cartridge. The accuracy of the cartridge is good, but not exceptional; various cartridges are capable of the same or better accuracy. A contributing factor in rifles is the transition of even a high-velocity cartridge projectile from supersonic to subsonic within 100 yd (91 m). As the bullet slows, the shock wave caused by supersonic travel overtakes the bullet and can disrupt its flight path, causing minor but measurable inaccuracies.

When zeroed for 100 yd (91 m), the arc-trajectory of the standard high-velocity .22 LR with a 40-gr bullet has a 2.7-inch (69 mm) rise at 50 yd (46 m), and a 10.8-inch (27 cm) drop at 150 yd (140 m).[10] A .22 LR rifle needs to be zeroed for 75 yd (69 m) to avoid overshooting small animals like squirrels at intermediate distances.[10]

As a hunting cartridge, rimfires are mainly used to kill small game up to the size of coyotes.[11] Although proper shot placement can kill larger animals such as deer or hog,[12] it is not recommended because its low power may not guarantee a humane kill.[13] The largest recorded animal killed with a .22 long caliber rifle was a grizzly bear in 1953.[14]

Because a .22 LR bullet is less powerful than larger cartridges, its danger to humans is often underestimated. In fact, a .22 LR bullet is capable of inflicting very serious injuries (e.g. the four people wounded, one mortally, during the Reagan assassination attempt) or death e.g. the Kauhajoki school shooting (11 killed and one wounded), the Jokela school shooting (eight killed and one wounded), and the 1979 Cleveland Elementary School shooting (two killed and nine wounded), as well as the assassination of Robert F. Kennedy. Numerous other shooting incidents have demonstrated that .22 LR bullets can easily kill or seriously injure humans.[15][16][17] Even after flying 400 yd (370 m), a .22 bullet is still traveling about 500 ft/s (150 m/s). Ricochets are more common in .22 LR projectiles than for more powerful cartridges as the combination of unjacketed lead and moderate velocities allows the projectile to deflect – not penetrate or disintegrate – when hitting hard objects at a glancing angle. A .22 LR can ricochet off the surface of water at a low angle of aim. Severe injury may result to a person or object in the line of fire on the opposite shore, several hundred yards away.[18]

Rimfire bullets are generally either plain lead with a wax coating (for standard-velocity loads) or plated with copper or gilding metal (for high-velocity or hyper-velocity loads). The thin copper layer on plated bullet functions as a lubricant reducing friction between the bullet and the barrel, thus reducing barrel wear. Plating also prevents oxidation of the lead bullet. Lead tends to oxidize if stored for long periods. On a plain lead bullet, oxide on the bullet's surface can increase its diameter enough to either prevent insertion of the cartridge into the chamber, or – with high velocity rounds – cause dangerously high pressures in the barrel, potentially rupturing the cartridge case and injuring the shooter; for that reason, standard and subsonic cartridges usually use a wax lubricant on lead bullets.

Subsonic rounds have a muzzle velocity of less than the speed of sound (about 1,080 ft/s (330 m/s)). These rounds are sometimes equipped with extra-heavy bullets of 46–61-grain (3.0–4.0 g) to improve the terminal ballistics of the slower projectile. Conversely, these rounds may contain little more than a primer and an extra-light bullet.

Subsonic rounds are favored by some shooters due to slightly superior accuracy and reduction in noise. Supersonic rounds produce a loud crack which can scare away animals when hunting. Accuracy is reportedly improved with subsonic rounds because a supersonic bullet (or projectile) that slows from supersonic to subsonic speed undergoes drastic aerodynamic changes in this transonic zone that might adversely affect the stability and accuracy of the bullet.[19]

Because the speed of sound in air at 68 °F (20 °C) is about 1,115 ft/s (340 m/s), the subsonic round's muzzle velocity is slightly below the speed of sound under many hunting conditions. However, under cold air conditions at 32 °F (0 °C), the speed of sound drops to 1,088 ft/s (332 m/s), approximately muzzle velocity. Hence, a "subsonic" round used below this temperature may be supersonic, and during the transition from supersonic to subsonic velocity, it may become unstable, reducing accuracy. To counteract this, some cartridge manufacturers have lowered the speed of their subsonic ammunition to 1,030 ft/s (310 m/s) or less.

Various combinations of subsonic rounds and semiautomatic .22 LR firearms result in unreliable cycling of the firearms' actions, as the result of insufficient recoil energy. Some subsonic rounds use heavier bullets (achieving lower velocities) to ensure, as a result of increased bullet mass, that enough energy is produced to cycle common blow-back actions.[20] As an example, the Aguila .22 LR SSS "Sniper SubSonic" round, has a 60-gr bullet on a .22 short case, providing the cartridge the same overall dimensions as a .22 long rifle round. However, other problems may be encountered: the heavier and longer bullet of the Aguila cartridge requires a faster barrel twist (by the Greenhill formula) to ensure the bullet remains stable in flight.

Two performance classes of .22 rimfire subsonic rounds exist. Some subsonic rounds, such as various .22 short and .22 long "CB" rounds, give about 700 ft/s (210 m/s) velocity with a 29-gr bullet providing relatively low impact energy (41 J at muzzle). These may not use any, or only small amounts of gunpowder, and have the characteristics of rounds intended only for indoor training or target practice rather than hunting. Where these are in .22 LR form, it is only to aid feeding in firearms designed for the cartridge, rather than older .22 CB shooting gallery rifles. The Aguila SSS gives about 950 ft/s (290 m/s) velocity with a 60-gr bullet offering energy (163 Joules) equivalent to many high velocity .22 long rifle rounds using standard 40-gr bullets. Other heavy-bullet subsonic rounds give similar performance, and are intended for hunting of small game, or control of dangerous animals, while avoiding excessive noise.

Schlierenhigh-speed video of a .22 LR travelling in free-flight demonstrating the air pressure dynamics surrounding the bullet

The velocity of standard-velocity .22 LR rounds varies between manufacturers. Some standard velocity ammo may be slightly supersonic-around 1,125 ft/s (343 m/s), other ammo such as CCI Standard Velocity .22 LR ammunition is rated at 1070 fps. Most standard velocity ammo has a bullet weight of 40 gr (2.6 g). Standard-velocity cartridges generate near or slightly supersonic velocities. These rounds generally do not develop these velocities in handguns because their short barrels do not take full advantage of the slower burning powder.[21]

The .22 long rifle round was originally loaded with black powder. The first smokeless powder loads were intended to match the standard velocity of the original black-powder rounds. Smokeless powder is more efficient than black powder, and the cartridge cases could hold more powder. Smokeless powder loads, called "high speed" or "high velocity", were offered by the major ammunition makers, giving a typical velocity increase of 8% (1,200 feet per second (370 m/s) to 1,300 feet per second (400 m/s)) while still using the standard 40-gr solid or 36-gr hollow-point lead bullet.

Many .22 LR cartridges use bullets lighter than the standard 40 gr, fired at even higher velocities. Hyper-velocity bullets usually weigh around 30 to 32 gr (1.9 to 2.1 g) and can have a muzzle velocity of 1,400 to 1,800 feet per second (430 to 550 m/s). This higher velocity is partially due to the use of lighter bullets.

The CCI Stinger was the first hyper-velocity .22 LR cartridge, and provided a significant increase in velocity and energy over standard rimfire rounds. The Stinger case is longer than that of the long rifle (about .71 in (18 mm) versus .595 in (15.1 mm) for the long rifle), but the plated hollow point bullet is lighter and shorter at 32 gr (2.1 g), giving the same overall length as the long rifle cartridge. (This longer case can cause ejection problems in some guns.) A powder with a slower burning rate is used to make the most use of the length of a rifle barrel. Most .22 long rifle powders increase velocity up to about 19 in (480 mm) of barrel.[22] The powder used in the Stinger increases velocity up to the longest .22 barrel length tested by the NRA, 26 in (660 mm).[23]

Later hyper-velocity rounds were introduced by other makers, based on the long rifle case with lighter bullets in the 30-gr weight range and slow-burning rifle powder loadings. The overall length of many of these cartridges was less than the overall length of the standard 40-gr bullet long rifle cartridge. One example is the Remington Viper; another is the Federal Spitfire.

The CCI Velocitor hyper-velocity round uses the standard long rifle case size and a standard weight 40 gr (2.6 g) bullet of proprietary hollow-point design to augment expansion and trauma. This cartridge has a muzzle velocity of 1,435 ft/s (437 m/s) and matches the overall length of the standard long rifle cartridge.

Special .22 LR caliber shot cartridges (No. 1 bore) usually loaded with No. 12 shot, have also been made. These are often called "snake shot," "bird shot" and "rat-shot" due to their use in very short range pest control. Such rounds have either a longer brass case that is crimped closed, or a translucent plastic "bullet" that contains the shot and shatters upon firing. In specially made .22-bore shotguns, the shot shells can be used for short-range skeet shooting and trap shooting at special, scaled-down, clay targets.

During World War II, a full metal jacket bullet version of the .22 LR was developed for the silenced High Standard HDM pistol.[24] The US Army Air Corps procured the Savage Model 24 .22 LR/.410 combination gun as an air crew survival weapon primarily to forage for game for food. The .22 LR full metal jacket bullet ammunition was issued with these firearms for military use to comply with treaty restrictions on expanding bullets.

The traditional .22 rimfire cartridges (BB, CB, short, long, extra long, and long rifle) differ in construction from more modern cartridges in the way the bullet is constructed and held in the case. Bullets for traditional .22 rimfires are the same outside diameter as the case but are constructed with a narrower cupped "heel" on the base of the bullet which is inserted into the case. The case mouth is then crimped around the heel, leaving exposed the majority of the bullet bearing surface that contacts the barrel of the gun. The bearing surface of .22 rimfire bullets is often lubricated and the surface is exposed to contamination. This was a common design in the early black powder cartridge era.

In later cartridges including the .22 WRF and .22 Magnum rimfires and modern centerfires, the bullet body is a uniform diameter and the bearing surface is inserted completely within the neck of the cartridge case, held in place by tension from the case neck around the bullet bearing surface (in some cartridges the case mouth maybe also be crimped into a cannelure (groove) in the bullet). The heeled bullet cartridge is considered weaker than the uniform diameter bullet cartridge which encloses the bearing surface of the bullet within the cartridge neck. Overall reliability of heeled bullet rimfire ammunition is high, but it is lower than the reliability of most centerfire ammunition.

The .22 LR uses a straight-walled case. Depending upon the type and the feed mechanism employed, a firearm that is chambered for .22 LR may also be able to safely chamber and fire the following shorter rimfire cartridges:

Today, rimfire rounds are mainly used for hunting small pests, for sports shooting, for plinking, and for inexpensive training. The .22 LR is the choice for several shooting events: biathlon, bullseye, plus divisions of benchrest shooting, metallic silhouette and pin shooting, most high school, collegiate, Boy Scouts of America, Project Appleseed, 4H shooting events, and many others. It is also used in the precision Rifle and Pistol shooting events at the Olympic Games. Good quality rimfire ammunition can be quite accurate. The main advantages are low cost, low recoil, low noise and high accuracy-to-cost ratio. The main disadvantage is its low power; it is better suited for use on small game and other small animals.[26]

As a defensive cartridge, it is considered inadequate, though the small size allows very lightweight, easily concealable handguns which can be carried in circumstances where anything larger would be impractical. Despite their limitations, people can use .22 LR pistols and rifles for defense, and are common simply because they are prevalent, inexpensive, and widely available.

Most semi-automatic rifles firing .22 LR cartridges will often only work properly when firing standard or high velocity rimfire ammunition, as the low recoil of subsonic rounds is insufficient to cycle the weapon's action. Rifles with manual actions do not have this problem. Due to the low bolt thrust of the .22 LR cartridge, most self-loading firearms chambered for the cartridge use the direct blowback operation system.

The tiny case of the .22 LR and the subsonic velocities (when using subsonic ammunition) make it well suited for use with a firearm suppressor (also known as silencers or sound moderators). The low volume of powder gases means that .22 LR suppressors are often no larger than a bull barrel; the Ruger 10/22 and Ruger MK II are common choices, because of their reliability and low cost, and the resulting product is often nearly indistinguishable from a bull barrel model (although weighing far less). Where firearm suppressors are only minimally restricted, a .22 LR firearm with a suppressor is often favored for plinking, as it does not require hearing protection or disturb the neighbors. Local government agencies sometimes use suppressed rimfire weapons for animal control, since dangerous animals or pests can be dispatched in populated areas without causing undue alarm.

The .22 LR has also seen limited usage by police and military snipers. Its main advantage in this role is its low noise, but it is usually limited to urban operations because of its short range.[27]

The Israeli military used a suppressed .22 LR rifle in the 1990s for riot control and to "eliminate disturbing dogs prior to operations", though it is now used less often as it has been shown to be more lethal than previously suspected.[27] Some other examples include the use of suppressed High Standard HDM pistols by the American OSS, which was the predecessor organization of the CIA.[24]Francis Gary Powers was issued a suppressed High Standard for the flight in which he was shot down. Suppressed Ruger MK II pistols were used by the US Navy SEALs in the 1990s.[28]

According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the .22 long rifle can handle up to 170.00 MPa (24,656 psi) Pmax piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.

Because the .22 long rifle round commonly uses a heeled lead or lightly plated bullet, the nominal bullet diameter is larger than the nominal bore diameter to prevent excessive lead fouling that can occur when shooting lead bullets that are the same or slightly smaller than the groove diameter. SAAMI specifies a nominal bullet diameter of 0.2255 with a tolerance of -0.004, while the specified bore diameter is 0.222.[30] In practice, 0.224 or slightly larger bullets are common, with barrel groove diameters commonly around 0.223.

Note: actual velocities are dependent on many factors, such as barrel length of a given firearm and manufacturer of a given batch of ammunition, and will vary widely in practice. The above velocities are typical.

^Fadala, Sam (1989). The Book of the Twenty-Two (1 ed.). South Hackensack, New Jersey: Stoeger Publishing Company. p. 249. ISBN978-0-88317-149-3. After the bullet glanced off of the water, its remaining velocity was 1195 fps. Only 43 fps were lost... The missile remains lethal after a ricochet.

1.
United States
–
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci

2.
Rifling
–
In firearms, rifling consists of helical grooves in the internal surface of a guns barrel, which impart a spin to a projectile around its long axis. This spin serves to stabilize the projectile, improving its aerodynamic stability. Rifling is often described by its twist rate, which indicates the distance the rifling takes to complete one revolution, such as 1 turn in 10 inches. A shorter distance indicates a faster twist, meaning that for a given velocity the projectile will be rotating at a spin rate. Barrels intended for long, small-diameter bullets, such as the ultra-low-drag, 80-grain 0.223 inch bullets, extremely long projectiles such as flechettes may require high twist rates, these projectiles must be inherently stable, and are often fired from a smoothbore barrel. Muskets were smoothbore, large caliber weapons using ball-shaped ammunition fired at low velocity. Due to the high cost and great difficulty of manufacturing, and the need to load readily from the muzzle. Consequently, on firing the ball bounced off the sides of the barrel when fired, barrel rifling was invented in Augsburg, Germany in 1498. In 1520 August Kotter, an armourer of Nuremberg, Germany improved upon this work, though true rifling dates from the mid-16th century, it did not become commonplace until the nineteenth century. The most successful weapons using rifling with black powder were breech loaders such as the Queen Anne pistol, the grooves most commonly used in modern rifling have fairly sharp edges. More recently, polygonal rifling, a throwback to the earliest types of rifling, has become popular, polygonal barrels tend to have longer service lives because the reduction of the sharp edges of the land reduces erosion of the barrel. Supporters of polygonal rifling also claim higher velocities and greater accuracy, polygonal rifling is currently seen on pistols from CZ, Heckler & Koch, Glock, Tanfoglio, and Kahr Arms, as well as the Desert Eagle. Such guns have achieved significant increases in velocity and range. Examples include the South African G5 and the German PzH2000, gain-twist rifling begins with very little change in the projectiles angular momentum during the first few inches of bullet travel after ignition during the transition from chamber to throat. This enables the bullet to remain undisturbed and trued to the case mouth. After engaging the rifling the bullet is progressively subjected to accelerated angular momentum as burning powder propels it down the barrel. By only gradually increasing the rate, torque is spread along a much longer section of barrel. Gain-twist rifling was used as early as the American Civil War, colt Army and Navy revolvers both employed gain-twist rifling

3.
Rimfire ammunition
–
Rimfire is a method of ignition for metallic firearm cartridges as well as the cartridges themselves. It is called rimfire because the pin of a gun strikes and crushes the bases rim to ignite the primer. Once the rim of the cartridge has been struck and the bullet discharged, while many other different cartridge priming methods have been tried since the 19th century, only rimfire technology and centerfire technology survive today in significant use. Frenchman Louis-Nicolas Flobert invented the first rimfire metallic cartridge in 1845 and his cartridge consisted of a percussion cap with a bullet attached to the top and the idea was to improve the safety of indoor shooting. In English-speaking countries, the Flobert cartridge corresponds to.22 BB, Rimfire cartridges are limited to low pressures because they require a thin case so that the firing pin can crush the rim and ignite the primer. Rimfire cartridges of.44 caliber up to.56 caliber were once common when black powder was used as a propellant, however, modern rimfire cartridges use smokeless powder which generates much higher pressures and tend to be of.22 caliber or smaller. Rimfire cartridges are typically inexpensive, primarily due to the inherent cost-efficiency of the ability to manufacture the cartridges in large lots, the price of metals used in the cartridges increased in 2002, the prices of the ammunition then further increased in 2012 possibly due to hoarding. The idea of placing a priming compound in the rim of the cartridge evolved from an 1831 patent, by 1845, this had evolved into the Flobert.22 BB Cap, in which the priming compound is distributed just inside the rim. The.22 BB Cap is essentially just a percussion cap with a round ball pressed in the front, intended for use in an indoor gallery target rifle, it used no gunpowder, but relied entirely on the priming compound for propulsion. Its velocities were very low, comparable to an airgun, the next rimfire cartridge was the.22 Short, developed for Smith & Wessons first revolver, in 1857, it used a longer rimfire case and 4 grains of black powder to fire a conical bullet. This led to the.22 Long, with the bullet weight as the short. This was followed by the.22 Extra Long with a longer than the.22 Long. The.22 Long Rifle is a.22 Long case loaded with the heavier Extra Long bullet intended for performance in the long barrel of a rifle. Larger rimfire calibers were used during the American Civil War in the Henry Repeater, the Spencer Repeater, the Ballard rifle and the Frank Wesson carbine. The early 21st century has seen a revival in interest in rimfire cartridges, a new and increasingly popular rimfire, the 17 HMR is based on a.22 WMR casing with a smaller formed neck which accepts a.17 bullet. The advantages of the 17 HMR over.22 WMR and other rimfire cartridges are its much flatter trajectory, the.17 HM2 is based on the.22 Long Rifle and offers similar performance advantages over its parent cartridge, at a significantly higher cost. While.17 HM2 sells for about four times the cost of.22 Long Rifle ammunition, it is significantly cheaper than most centerfire ammunition. A notable rimfire cartridge that is still in production in Europe and this cartridge can fire a small ball, but is primarily loaded with a small amount of shot, and used in smoothbore guns as a miniature shotgun, or garden gun

4.
Ammunition
–
Ammunition is the general term used for the material fired, scattered, dropped or detonated from any weapon. The term ammunition can be traced back to the mid 17th century, broadly speaking, ammunition refers to both expendable weapons and the component parts of other weapons that create the effect on a target. Nearly all weapons will require some form of ammunition to operate, the word comes from the French la munition, which refers to the material used for war. The terms ammunition and munitions are used interchangeably, although the term munition now usually refers to both the actual weapons system alongside the ammunition required to operate it. The purpose of ammunition is to project a force against a target to have an effect. The most iconic example of ammunition is the cartridge, which all components required to deliver the weapon effect in a single package. Ammunition comes in a range of sizes and types and is often designed to work only in specific weapons systems. However, there are internationally recognized standards for certain types that enable their use across different weapons. There are also types of ammunition that are designed to have a specialized effect on a target, such as armor-piercing shells and tracer ammunition. Ammunition is commonly colored in a manner to assist in the identification. A round is a cartridge containing a projectile, propellant, primer. A shell is a form of ammunition that is fired by a large cannon or artillery piece. Before the mid-19th century, these shells were made of solid materials. However, since that time, they are often filled with high-explosives. A shot refers to a release of a weapons system. This may involve firing just one round or piece of ammunition, a dud refers to loaded ammunition that fails to function as intended, typically failing to detonate on landing. However, it can refer to ammunition that fails to fire inside the weapon, known as a misfire, or when the ammunition only partially functions. Dud ammunition, which is classified as an ordnance, is regarded as highly dangerous

5.
Pistol
–
A pistol is a type of handgun. In some usage, the term refers to a subset of handguns. In other usage, the term is interchangeable with handgun, some handgun experts and dictionaries make a technical distinction that views pistols as a subset of handguns, others use the terms interchangeably. But UK/rest of Commonwealth usage does not always make this distinction, for example, the official designation of the Webley Mk VI revolver was Pistol, Revolver, Webley, No.1 Mk VI. The English word was introduced in ca.1570 from the Middle French pistolet, the etymology of the French word pistolet is disputed. The first suggestion derives the word from Czech píšťala, a type of hand-cannon used in the Hussite Wars during the 1420s, the Czech word was adopted in German as pitschale, pitschole, petsole, and variants. The second suggestion is less likely, the use of the word as a designation of a gun is not documented before 1605 in Italy, long after it was used in French, the Czech word is well documented since the Hussite wars in 1420s. Other suggestions include from Middle High German pischulle or from Middle French pistole, also it is suggested that early pistols were carried by cavalry in holsters hung from the pommel of a horses saddle. The most common types of pistol are the shot. Single shot handguns were mainly seen during the era of flintlock and musket weaponry where the pistol was loaded with a ball and fired by a flint striker. However, as technology improved, so did the single shot pistol, new operating mechanisms were created, and due to this, they are still made today. It is the oldest type of pistol, and is used to hunt wild game. Multi-barreled pistols were common during the time as single shot pistols. As designers looked for ways to increase fire rates, multiple barrels were added to all guns including pistols, one example of a multi-barreled pistol is the Ducks foot pistol, which generally had either four or eight barrels, although some 20th century models had three barrels. Around 1850, pistols such as the Jarre harmonica gun were produced that had a sliding magazine, the sliding magazine contained pinfire cartridges or speedloaders. The magazine needed to be moved manually in many designs, hence distinguishing them from semi-automatic pistols, with the development of the revolver in the 19th century, gunsmiths had finally achieved the goal of a practical capability for delivering multiple loads to one handgun barrel in quick succession. The semi-automatic pistol was the step in the development of the pistol. By avoiding multiple chambers—which need to be individually reloaded—semi-automatic pistols delivered faster rates of fire, an example of a modern blow back action semi-automatic pistol is the HK VP70

6.
Revolver
–
A revolver is a repeating handgun that has a revolving cylinder containing multiple chambers and at least one barrel for firing. Revolvers might be regarded as a subset of pistols, or as a subset of handguns. Though the term revolver usually only refers to handguns, other firearms may also have a revolving chamber and these include some models of grenade launchers, shotguns, and rifles. Most revolvers contain five or six rounds in the cylinder, though the original name was revolving gun, the short-hand revolver is universally used. The revolver allows the user to fire multiple rounds without reloading, each time the user cocks the hammer, the cylinder revolves to align the next chamber and round with the hammer and barrel, which gives this type of firearm its name. In a single-action revolver, the user pulls the back with his free hand or thumb. In a double-action revolver, pulling the trigger moves the back, then releases it. Loading and unloading a double-action revolver requires the operator to swing out the cylinder and insert the proper ammunition, the first guns with multichambered cylinders that revolved to feed one barrel were made in the late 16th century in Europe. They were expensive and rare curiosities, not until the 19th century would revolvers become common weapons of industrial production. One of the first was a flintlock revolver patented by Elisha Collier in 1814, the first percussion revolver was made by Lenormand of Paris in 1820 and the first percussion cap revolver was invented by the Italian Francesco Antonio Broccu in 1833. He received a prize of 300 francs for his invention, although he did not patent it, however, in 1835 a similar handgun was patented by Samuel Colt, who would go on to make the first mass-produced revolver. The first cartridge revolvers were produced around 1854 by Eugene Lefaucheux, revolvers soon became standard for nearly all uses. In the early 20th century, semi-automatic pistols were developed, which can hold more rounds, Automatic pistols also have a flat profile, more suitable for concealed carry. Automatic pistols have almost completely replaced revolvers in military and law enforcement use, revolvers still remain popular as back-up and off-duty handguns among American law enforcement officers and security guards. Also, revolvers are still common in the American private sector as defensive, in the development of firearms, an important limiting factor was the time it took to reload the weapon after it was fired. While the user was reloading, the weapon was useless, several approaches to the problem of increasing the rate of fire were developed, the earliest being multi-barrelled weapons which allowed two or more shots without reloading. Later weapons featured multiple barrels revolving along a single axis, the earliest examples of what today is called a revolver were made in Germany in the late 16th century. These weapons featured a barrel with a revolving cylinder holding the powder

7.
Submachine gun
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A submachine gun is a magazine-fed, automatic carbine designed to fire pistol cartridges. The term submachine gun was coined by John T. Thompson, the submachine gun was developed during World War I. At its zenith during World War II, millions of SMGs were made, after the war, new SMG designs appeared frequently. However, by the 1980s, SMG usage decreased, today, submachine guns have been largely replaced by assault rifles, which have a greater effective range and are capable of penetrating the helmets and body armor used by modern infantrymen. Carbine-type automatic weapons firing pistol rounds were developed during the stages of World War I by Italy, Germany. Their improved firepower and portability offered an advantage in trench warfare, in 1915, the Italians introduced the Villar-Perosa aircraft machine gun. It fired pistol-caliber 9mm Glisenti ammunition, but was not a true submachine gun and this odd design was then modified into the Beretta OVP carbine-type submachine gun, which then evolved into the Beretta Model 1918 after the end of World War I. Both the Beretta OVP and the Model 1918 had a wooden stock, a 25-round top-fed box magazine. The Germans initially used heavier versions of the P08 pistol equipped with a larger-capacity snail-drum magazine, by 1918, Bergmann Waffenfabrik had developed the MP18, the first practical submachine gun. This weapon fired the 9×19mm Parabellum round and used the same 32-round snail-drum magazine as the Luger P-08, the MP18 was used in significant numbers by German stormtroopers employing infiltration tactics, achieving some notable successes in the final year of the war. However, these were not enough to prevent Germanys collapse in November 1918, after World War I, the MP18 would evolve into the MP28/II SMG, which incorporated a simple 32-round box magazine, a semi & full auto selector, and other minor improvements. The Thompson submachine gun had been in development at approximately the time as the Bergmann. However, the war ended before prototypes could be shipped to Europe, although it had missed its chance to be the first purpose-designed submachine gun to enter service, it became the basis for later weapons and had the longest active service life of the three. However, the FBI and other U. S. police forces themselves showed no reluctance to use, eventually, the submachine gun was gradually accepted by many military organizations, especially as World War II loomed, with many countries developing their own designs. The Italians were among the first to develop submachine guns during World War I, however, they were slow to produce them during World War II. The Beretta Model 1938 was not available in numbers until 1943. The 38 was made in a series of improved and simplified models all sharing the same basic layout. The Beretta has two triggers, the front for semi-auto and rear for full-auto, most models use standard wooden stocks, although some models were fitted with an MP 40-style under-folding stock and are commonly mistaken for the German SMG

8.
Shotgun
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Shotguns come in a wide variety of sizes, ranging from 5. A shotgun is generally a smoothbore firearm, which means that the inside of the barrel is not rifled, preceding smoothbore firearms, such as the musket, were widely used by armies in the 18th century. The direct ancestor to the shotgun, the blunderbuss, was used in a similar variety of roles from self-defense to riot control. It was often used by cavalry troops because of its shorter length and ease of use. In the 19th century, however, these weapons were replaced on the battlefield with breechloading rifled firearms. The military value of shotguns was rediscovered in the First World War, since then, it has been used in a variety of roles in civilian, law enforcement, and military applications. The shot pellets from a spread upon leaving the barrel, and the power of the burning charge is divided among the pellets. In a hunting context, this makes shotguns useful primarily for hunting birds, however, in a military or law enforcement context, the large number of projectiles makes the shotgun useful as a close quarters combat weapon or a defensive weapon. Militants or insurgents may use shotguns in asymmetric engagements, as shotguns are commonly owned civilian weapons in many countries, shotguns are also used for target shooting sports such as skeet, trap, and sporting clays. These involve shooting clay disks, known as clay pigeons, thrown in various ways, shotguns come in a wide variety of forms, from very small up to massive punt guns, and in nearly every type of firearm operating mechanism. The common characteristics that make a unique center around the requirements of firing shot. These features are the typical of a shotgun shell, namely a relatively short, wide cartridge, with straight walls. Ammunition for shotguns is referred to in the USA as shotgun shells, shotshells, the term cartridges is standard usage in the United Kingdom. The shot is fired from a smoothbore barrel, another configuration is the rifled slug barrel. The typical use of a shotgun is against small and fast moving targets, the spreading of the shot allows the user to point the shotgun close to the target, rather than having to aim precisely as in the case of a single projectile. The disadvantages of shot are limited range and limited penetration of the shot, which is why shotguns are used at short ranges, and typically against smaller targets. Larger shot sizes, up to the case of the single projectile slug load, result in increased penetration. Aside from the most common use against small, fast moving targets, First, it has enormous stopping power at short range, more than nearly all handguns and many rifles

9.
Boy Scouts of America
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The BSA was founded in 1910 and, since then, more than 110 million Americans have been participants in BSA programs at some time. The BSA is part of the international Scout Movement and became a member organization of the World Organization of the Scout Movement in 1922. In order to further these activities, the BSA has four high-adventure bases, Northern Tier, Philmont Scout Ranch, Sea Base. The traditional Scouting divisions are Cub Scouting for boys ages 7 to 10½ years, Boy Scouting for boys ages 10½ to 18, Learning for Life is a non-traditional subsidiary that provides in-school and career education. Units are led entirely by volunteers appointed by the chartering organization, the progressive movement in the United States was at its height during the early 20th century. With the migration of families from farms to cities, there were concerns among some people that men were no longer learning patriotism and individualism. The YMCA was a promoter of reforms for young men with a focus on social welfare and programs of mental, physical, social. In 1907, Robert Baden-Powell, founded the Scouting movement in England using elements of Setons works among other influences, several Scout programs for boys started independently in the US. Many of these Scout programs in the US merged with the BSA.52 In 1909, Chicago publisher W. D. Boyce was visiting London, Boyce was lost on a foggy street when an unknown Scout came to his aid, guiding him to his destination. The boy then refused Boyces tip, explaining that he was a Boy Scout and was doing his daily good turn. Interested in the Boy Scouts, Boyce met with staff at the Boy Scouts Headquarters and, by some accounts, upon his return to the US, Boyce incorporated the Boy Scouts of America on February 8,1910. Edgar M. Robinson and Lee F. Hanmer became interested in the nascent BSA, Robinson enlisted Seton, Beard, Charles Eastman, and other prominent leaders in the early youth movements. Former president Theodore Roosevelt, who had complained of the decline in American manhood. The current mission statement of the BSA is to young people to make ethical and moral choices over their lifetimes by instilling in them the values of the Scout Oath. The BSA holds a congressional charter under Title 36 of the United States Code, on behalf of the BSA, Paul Sleman, Colin H. Livingstone, Ernest S. Martin, and James E. West successfully lobbied Congress for a charter for the BSA which President Woodrow Wilson signed on June 15,1916. The special recognition neither implies nor accords Congress any special control over the BSA, in the BSA, Scouting is considered to be one movement with four main programs, Cub Scouting is available to boys from first to fifth-grade or 7 to 11 years. Boy Scouting is the program of the BSA generally for boys ages 11 to 18

10.
Colt AR-15
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The Colt AR-15 is a lightweight,5. 56×45mm, magazine-fed, air-cooled semi-automatic, gas-operated rifle with a rotating bolt. It was designed to be manufactured with the use of aluminum alloys. Introduced in 1964, Colt has made many different types of AR-15 rifle and carbine models, including the AR-15, AR-15A2, AR-15A3, Sporter, HBAR, Government, Target, Match and it is based on the ArmaLite AR-15 rifle, a select-fire weapon intended for military sales. In 1959, ArmaLite sold the design to Colt due to financial difficulties, after some modifications, the rifle eventually became the United States military M16 rifle. Shortly thereafter, Colt began to make semi-automatic versions for civilian sales, the term AR-15 is a Colt registered trademark, which they use to denote only the semi-automatic rifle versions available for civilian and law enforcement sales. The term AR-15 signifies Armalite rifle, design 15, other manufacturers make AR-15 clones and variants marketed under separate designations, although these are frequently referred to as AR-15s. This article discusses the semiautomatic version manufactured by Colt, the Colt AR-15 is based on the 5.56 mm ArmaLite AR-15 rifle, which is a smaller lighter version of the 7.62 mm ArmaLite AR-10. Both of these rifles were designed by Eugene Stoner, Robert Fremont, in 1959, ArmaLite sold its rights to the AR-10 and AR-15 to Colt. After a Far East tour, Colt made its first sale of Colt made ArmaLite AR-15 rifles to Malaya on September 30,1959, Colt manufactured their first batch of 300 select-fire Colt ArmaLite AR-15 Model 01 rifles in December 1959. Colt marketed the Colt made ArmaLite AR-15 rifle to various military services around the world, after modifications, the new redesigned rifle was adopted by the United States military as the M16 rifle. Most Colt ArmaLite AR-15 rifles in U. S. service have long ago been upgraded to M16 rifle configuration, Colt continued to use the AR-15 trademark for its semi-automatic variants that were marketed to civilian and law-enforcement customers. The original AR-15 was a lightweight weapon, weighing less than 6 pounds with empty magazine. Later heavy-barrel versions of the civilian AR-15 can weigh upwards of 8.5 lb, patent 2,951,424 describes the cycling mechanism used in the original AR-15. The bolt carrier acts as a cylinder and the bolt itself acts as a stationary piston. This mechanism is called direct gas impingement, although it differs from prior gas systems. Stoner did not consider the AR-15 to be a direct impingement mechanism. Gas is tapped from the barrel as the bullet moves past a gas port located above the front sight base. The gas expands into the port and down a gas tube, here, the gas tube protrudes into a gas key, which accepts the gas and funnels it into the bolt carrier

High-speed photography is the science of taking pictures of very fast phenomena. In 1948, the Society of Motion Picture …

Nuclear explosion photographed by rapatronic camera less than 1 millisecond after detonation. The fireball is about 20 meters in diameter. The spikes at the bottom of the fireball are due to what is known as the rope trick effect.

A 5 millisecond capture of coffee blown out of a straw.

A droplet is caught with a strobe after rebounding upward.

The exhaust-fan in this photograph was rotating at its full-speed when the photo was taken.

A cartridge is a type of firearm ammunition packaging a projectile (bullet, shots or slug), a propellant substance …

A modern cartridge consists of the following: 1. the bullet, as the projectile; 2. the case, which holds all parts together; 3. the propellant, for example gunpowder or cordite; 4. the rim, which provides the extractor on the firearm a place to grip the casing to remove it from the chamber once fired; 5. the primer, which ignites the propellant.

External ballistics or exterior ballistics is the part of ballistics that deals with the behavior of a projectile in …

Typical trajectory graph for a M4 carbine and M16A2 rifle using identical M855 cartridges with identical projectiles. Though both trajectories have an identical 25 m near zero, the difference in muzzle velocity of the projectiles gradually causes a significant difference in trajectory and far zero. The 0 inch axis represents the line of sight or horizontal sighting plane.

A full metal jacket (FMJ) bullet is a small-arms projectile consisting of a soft core (often lead) encased in a shell …

These .30-caliber (7.62 mm) full metal jacket bullets show the typical jacket openings exposing the lead alloy core on the base of the bullet to illustrate a full metal jacket may not completely enclose the core.

A sonic boom is the sound associated with the shock waves created by an object traveling through the air faster than …

New research is being performed at NASA's Glenn Research Center that could help alleviate the sonic boom produced by supersonic aircraft. Testing was recently completed of a Large-Scale Low-Boom supersonic inlet model with micro-array flow control. A NASA aerospace engineer is pictured here in a wind tunnel with the Large-Scale Low-Boom supersonic inlet model.

The speed of sound is the distance travelled per unit time by a sound wave as it propagates through an elastic medium. …

Image: FA 18 Hornet breaking sound barrier (7 July 1999) filtered

Density and pressure decrease smoothly with altitude, but temperature (red) does not. The speed of sound (blue) depends only on the complicated temperature variation at altitude and can be calculated from it, since isolated density and pressure effects on the speed of sound cancel each other. Speed of sound increases with height in two regions of the stratosphere and thermosphere, due to heating effects in these regions.